526 research outputs found

    Active inference, evidence accumulation, and the urn task

    Get PDF
    Deciding how much evidence to accumulate before making a decision is a problem we and other animals often face, but one that is not completely understood. This issue is particularly important because a tendency to sample less information (often known as reflection impulsivity) is a feature in several psychopathologies, such as psychosis. A formal understanding of information sampling may therefore clarify the computational anatomy of psychopathology. In this theoretical letter, we consider evidence accumulation in terms of active (Bayesian) inference using a generic model of Markov decision processes. Here, agents are equipped with beliefs about their own behavior--in this case, that they will make informed decisions. Normative decision making is then modeled using variational Bayes to minimize surprise about choice outcomes. Under this scheme, different facets of belief updating map naturally onto the functional anatomy of the brain (at least at a heuristic level). Of particular interest is the key role played by the expected precision of beliefs about control, which we have previously suggested may be encoded by dopaminergic neurons in the midbrain. We show that manipulating expected precision strongly affects how much information an agent characteristically samples, and thus provides a possible link between impulsivity and dopaminergic dysfunction. Our study therefore represents a step toward understanding evidence accumulation in terms of neurobiologically plausible Bayesian inference and may cast light on why this process is disordered in psychopathology

    On the Relationship between the Uniqueness of the Moonshine Module and Monstrous Moonshine

    Full text link
    We consider the relationship between the conjectured uniqueness of the Moonshine Module, V♼{\cal V}^\natural, and Monstrous Moonshine, the genus zero property of the modular invariance group for each Monster group Thompson series. We first discuss a family of possible ZnZ_n meromorphic orbifold constructions of V♼{\cal V}^\natural based on automorphisms of the Leech lattice compactified bosonic string. We reproduce the Thompson series for all 51 non-Fricke classes of the Monster group MM together with a new relationship between the centralisers of these classes and 51 corresponding Conway group centralisers (generalising a well-known relationship for 5 such classes). Assuming that V♼{\cal V}^\natural is unique, we then consider meromorphic orbifoldings of V♼{\cal V}^\natural and show that Monstrous Moonshine holds if and only if the only meromorphic orbifoldings of V♼{\cal V}^\natural give V♼{\cal V}^\natural itself or the Leech theory. This constraint on the meromorphic orbifoldings of V♼{\cal V}^\natural therefore relates Monstrous Moonshine to the uniqueness of V♼{\cal V}^\natural in a new way.Comment: 53 pages, PlainTex, DIAS-STP-93-0

    Efficient, full-spectrum, long-lived, non-toxic microwave lamp for plant growth

    Get PDF
    Fusion Systems Corporation has developed a mercury-free, low infrared, efficient microwave lamp using a benign sulfur based fill optimized for visible light. Our literature search and discussions with researchers directed us to enhance the bulbs red output. We have demonstrated a photosynthetic efficacy of over 2 micro-moles per microwave joule which corresponds to over 1.3 micro-moles per joule at the power main. Recent work has shown we can make additional increases in overall system efficiency. During the next two years, we expect to demonstrate a system capable of producing more than 1.5 micro-moles/joule measured at the power main with significantly less IR than alternative lamp systems. We determined optimal plant growth light requirements via a literature search and researcher input. We surveyed candidate lamp fill materials to be used in combination with sulfur and explored several methods of increasing photosynthetic efficacy

    Complete High Temperature Expansions for One-Loop Finite Temperature Effects

    Get PDF
    We develop exact, simple closed form expressions for partition functions associated with relativistic bosons and fermions in odd spatial dimensions. These expressions, valid at high temperature, include the effects of a non-trivial Polyakov loop and generalize well-known high temperature expansions. The key technical point is the proof of a set of Bessel function identities which resum low temperature expansions into high temperature expansions. The complete expressions for these partition functions can be used to obtain one-loop finite temperature contributions to effective potentials, and thus free energies and pressures.Comment: 9 pages, RevTeX, no figures. To be published in Phys. Rev D. v2 has revised introduction and conclusions, plus a few typographical errors are corrected; v3 corrects one typ

    Results of the 2016 Indianapolis Biodiversity Survey, Marion County, Indiana

    Get PDF
    Surprising biodiversity can be found in cities, but urban habitats are understudied. We report on a bioblitz conducted primarily within a 24-hr period on September 16 and 17, 2016 in Indianapolis, Indiana, USA. The event focused on stretches of three waterways and their associated riparian habitat: Fall Creek (20.6 ha; 51 acres), Pleasant Run (23.5 ha; 58 acres), and Pogue’s Run (27.1 ha; 67 acres). Over 75 scientists, naturalists, students, and citizen volunteers comprised 14 different taxonomic teams. Five hundred ninety taxa were documented despite the rainy conditions. A brief summary of the methods and findings are presented here. Detailed maps of survey locations and inventory results are available on the Indiana Academy of Science website (https://www.indianaacademyofscience.org/)

    The third Symptom Management Research Trial in Oncology (SMaRT Oncology-3): a randomised trial to determine the efficacy of adding a complex intervention for major depressive disorder (Depression Care for People with Lung Cancer) to usual care, compared to usual care alone in patients with lung cancer

    Get PDF
    Background: Depression Care for People with Lung Cancer is a complex intervention delivered by specially trained cancer nurses, under the supervision of a psychiatrist. It is given as a supplement to the usual care for depression, which patients receive from their general practitioner and cancer service. The third Symptom Management Research Trial in Oncology (SMaRT Oncology-3 Trial) will test its efficacy when compared to usual care alone. Design: A two arm parallel group multi-centre randomised controlled trial. 200 patients will be recruited through established systematic Symptom Monitoring Services, which screen patients for depression. Patients will have: a diagnosis of lung cancer; an estimated life expectancy of three months or more and a diagnosis of Major Depressive Disorder. Patients will be randomised to usual care or usual care plus Depression Care for People with Lung Cancer. Randomisation will be carried out by telephoning a secure computerised central randomisation system or by using a secure web interface. The primary outcome measure is average depression severity. This will be assessed using scores on the 20-item Symptom Hopkins Checklist (SCL-20D), collected every four weeks over 32 weeks. Secondary outcomes include severity of anxiety, pain and fatigue; self-rated improvement of depression; quality of life and satisfaction with depression care

    Aminooxy-BCN glycoconjugates

    Get PDF
    NMR spectroscopy data for aminooxybicyclononyne derivatives and glycan conjugates and protein mass spectrometry data for protein ligation reaction

    The Baryon asymmetry in the Standard Model with a low cut-off

    Get PDF
    We study the generation of the baryon asymmetry in a variant of the standard model, where the Higgs field is stabilized by a dimension-six interaction. Analyzing the one-loop potential, we find a strong first order electroweak phase transition for Higgs masses up to at least 170 GeV. Dimension-six operators induce also new sources of CP violation. We compute the baryon asymmetry in the WKB approximation. Novel source terms in the transport equations enhance the generated baryon asymmetry. For a wide range of parameters the model predicts a baryon asymmetry close to the observed value.Comment: 22 pages, latex, 6 figure
    • 

    corecore